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# Motor Starting Calculation (MS Excel Spreadsheet)

## Motor starting case studies

A motor starting case study for any given electrical network can be performed by reducing the network to a smaller equivalent network consisting of a source (generator/grid), the starting motor (largest motor), another large running motor, and a lumped load. This MS Excel-based spreadsheet is based on this concept and presents a small model of an electrical network that can be adapted for such motor starting case studies.

This is very helpful especially for quick checks as follows:

1. What is the largest motor size that can be started with a given generator rating
2. What should be the rating of the generator (or nos of generator operated in parallel) for a given load and largest motor size
3. Knowing voltage drop during starting conditions for given motor details and hence deciding the key parameter during design (say max allowable starting current)
4. Deciding the cable size/number of runs etc.

The spreadsheet performs an iterative calculation based on pre-start load inputs and starting motor data. The detailed analysis may be performed with the help of available software.

### Notes:

1. Motor starting analyses are generally performed for the largest motor connected to a switchboard.
2. For worst-case results, motor starting analyses are generally performed considering the weakest source.
3. Considering the above two facts, any given electrical network, where a starting analysis of a motor is required, can be reduced to a simplified network consisting of a source (generator/s or grid), the starting motor (largest motor), the running motor/s (second largest motor/s or motor of the same rating as the largest motor understudy) and other loads lumped together.
4. Modeling
This spreadsheet allows the user to model a given network as follows:

1. Generator/s: The details of one generator shall be entered. If there is more than one generator of identical rating, these can be modeled simply by entering the number of the generator in parallel.
2. Grid: The details of the grid shall be entered
3. Transformer/s: The details of one transformer shall be entered. If there is more than one transformer of identical rating, these can be modeled simply by entering the number of the transformer in parallel.
4. The spreadsheet considered either the “Generator/s” or the “Grid” supply for the motor starting the analysis. The “source for the motor starting analysis” can be selected via the drop-down menu. The selection automatically simulates switching “ON” or “OFF” the respective source breaker.
5. Starting Motor: The details of the largest motor connected to the switchboard shall be entered.
6. Running Motor/s: The details of the second largest running motor/s (or motor of rating same as the starting motor) connected to the switchboard shall be entered. This model can also be utilized by the user to check the voltage drop at the terminals of any remote motor/s.
7. Lumped Load: The details of the remaining load on the switchboard can be modeled as a lumped load. The % motor can be defined which shall be modeled as constant power load while the remaining % of load shall be modeled as constant impedance load for the calculation.
8. Error in data entry of the “voltage” input shall be highlighted if bus voltages are much different from the generator terminal voltage input of transformer voltage ratio inputs.

The excel spreadsheet has 2 sheets as follows:

• Sheet title “Preface” with notes explaining the calculation spreadsheet and the summary about the software and
• Sheet title ” Motor starting calculation” where actual data entry and calculations can be performed
 Software: Motor Starting Calculation Version: 1.0 Developer: Hemant Kashikar Size: 104 Kb Price: – Download: Here 🔗 (Get Premium Membership) | Video Courses | Download Updates

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1. terry mulligan
Nov 09, 2023

How can I get a copy of the Motor Start calculator spread sheet please?

2. Marco Iezzi
Sep 04, 2023

Hi I’am interested in this case study. How do I download it?

3. khalid Naeim
Sep 04, 2023

Thank you very much for your effort.

Best Wishes

4. Khulekani Nyathi
Mar 13, 2023

interested in formulae

5. Awel
Nov 26, 2022

6. kumar swamy G
Sep 10, 2022

i needed calculation chart and course

7. Dennis Taal
Jun 04, 2022

I find your program very informative and solution to basic designing. Thank you.

8. Fabian Dulay
Apr 28, 2022

Pls share the excel password

9. Edgardo Ramirez
Apr 27, 2022

I am interested on this motor starting case study.

10. Jan Roets
Nov 27, 2021

Good Day Hemant

Thank You for this information.
I am not on your level regarding this, but I am going to try and use this to do calculation for an small open cast mine with about 50 380v motors of different size.
Thank You
Jan

11. CALIXTO Morales Bantayan
Aug 10, 2021

How much the cost of your excel program?

12. mokhtr
Mar 31, 2021

how calculator eaffact transient vacuum circuit large indction motor 1100kw 11kv and how calculator all parmater

13. Kaushal Bhagat
May 17, 2020

This excel is password protected. Can u share the password to open this file

• khalid Naeim
Mar 28, 2023

Thanks for your excellent effort.
Please I need copy of this calculation
Best Wishes

14. Ram Prakash Sharma
Sep 11, 2019

Service provider

15. Fairoz Ahamed
Sep 02, 2019

Dear Sir,

16. Durgaiah Sangepu
Sep 02, 2019

This excel is password protected. Can u share the password to open this file.

17. RatnaKumar
Jul 18, 2019

Kindly send sample sheets.

18. Alpha king
Feb 20, 2019

Good souces!Thanks!

19. Khaled Ellithy
Jan 25, 2018

Thanks; Excellent for VDIP due to large motor starting;

20. Khaled Ellithy
Jan 25, 2018

Thanks to you all. I have got a lot of useful materials in power systems area for my students

Professor
Ellithy

21. Musse Mohamud Ahmed
Jan 05, 2018

Very good arrangements Guys, thank you very much.

22. bhavin patel
Dec 10, 2016

dear sir
can u please send me a detail example for the above excel sheet

23. Vikram
Jul 05, 2016

Its an awesome workout and very useful.

24. ANIL
Feb 14, 2016

Could not enter value generator voltage 6600 v for solo generator mode

• PIERO VERCELLINO
Mar 30, 2019

Dear Sirs,
many thanks to share your knowledge
On excel file i can’t change selection from main grid to generator grid (generator ON grid OFF)

Thanks

Piero Vercellino

25. FELIX JR.
Feb 14, 2016

THIS IS GOOD EXCEL PROGRAM IN THE CALCULATION OF % VOLTAGE STARTING DIP WHEN A LARGE MOTOR IS TARTED SUDDENLY EVEN WHEN ALREADY THERE’S EXISTING LOADS RUNNING.

26. Boomi
May 13, 2015

Very much informative and I like all spreadsheets
Regards,
Boomi

27. Jason Buda
Apr 21, 2015

The excel spreadsheet downloaded just fine for me… It is very involved and I am looking forward to picking at it to fully understand how to use it. The introduction sheet seems very intuitive! Thanks for sharing!

28. Abdulwahid
Jan 15, 2015

29. Rakesh Dhedhi
Sep 11, 2014

Dear Sir / Ma’am,
First of all thanks for making such beautiful site for electrical world.

Problem:
1. By right click option : It saves html page instead of excel or other file.
2. By box.com : We’re sorry, the server encountered an unexpected error.

I hope admin will rectify this problem asap.
Thanking you in anticipation.

With best Regards,
Rakesh Dhedhi
Electrical Engineer

30. Denis Milton
Aug 27, 2014

Motor Starting Calculation-Rev1.xls

We’re sorry, the server encountered an unexpected error.

31. VICTOR RAUTA
Aug 26, 2014

INTERESTING ENGAGEMENT,
LOVING IT

32. Melvin
Jul 16, 2014

33. Alfredo Labung
Mar 28, 2014

keen to know more about articles, software, guides & lectures of EEP tech refs as well…

34. Nitin
Feb 21, 2014

Not able to download excel sheets…plz help

• Edvard
Feb 21, 2014

35. nandaarief
Nov 19, 2013

thanks a lot, its very helpfull

36. saunak
Sep 23, 2013

This site is really excellent i m very thankfull…it can be change my life electrical engineering….
thank you soo much eep.

37. Ashraf
Jul 25, 2013

I am not able to download the excel sheet

38. karthikeyan
Apr 09, 2013

hi guys.. i am fresher to engineering…
i would like to learn how motor starting calculation is done.
please send me some technical articles/books in this regard to y mail id ([email protected])

39. WillG72
Mar 02, 2013

I cannot download either. I did as you advised about clearing the cache. When I click on ‘Download’, I am taken to a preview page called ‘Box’ and states that I need to login to it. I never heard of this and why do I need to login to some other site?
William

40. munis.munnu
Oct 29, 2012

i am not able to download the excel sheet….

41. natemp
Jul 03, 2012

The worksheet not producing resuts for the below combination (even though this is not praticle)
Transformer for voltage rating 11/0.2kV
All loads with 0.2kV
V2 bus voltage 0.2kV

Please advise how to over come this issue

thanks

42. mpsaxena2003
Nov 01, 2011

I have made a vba macro in MS Excel for Transformer Sizing .I want to upload it in this site. How i do it.

43. ajay34
Aug 17, 2011

why i cant download.. Motor Starting Calculation…

• Edvard
Aug 17, 2011

Logout and clear the cache in your browser and then login again. It should work. There was some works and improvements on EEP, so try to clear your cache.

BR

• WillG72
Mar 02, 2013